/*
 * Alloy Analyzer
 * Copyright (c) 2002 Massachusetts Institute of Technology
 *
 * The Alloy Analyzer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Alloy Analyzer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the Alloy Analyzer; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package alloy.bool;

/** Boolean "constant" whose value depends on the current value of a {@link BoolSwitch}.
    If the {@link BoolSwitch} has a particular value, this constant is true, else false.
    @see SetVarExpr */
class VarConst extends BooleanFormula {
    /** {@link BoolSwitch} on which value of this const depends. */
    final BoolSwitch var;
    /** Value which {@link #_var} must have for this {@link VarConst} to be true. */
    final long val;

    VarConst(BoolSwitch var_, long val_) { this.var = var_; this.val = val_; }

    protected boolean checkConstantValued() { return true; }

    protected Object handleVisitor(GBF_V visitor_) { return visitor_.forVarConst(this); }
    int getNumVars() { return 0; }

    public String toString() { return "[VarConst: " + var + "=" + val + "]"; }
}
